Fix redirects in dev mode (#7342)

* Fix redirects in dev mode

* Adding a changeset

4 files changed, 109 insertions, 54 deletions

diff --git a/.changeset/swift-flies-press.md b/.changeset/swift-flies-press.md
new file mode 100644
index 000000000..f57237d0e
--- /dev/null
+++ b/.changeset/swift-flies-press.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fix for experimental redirects in dev mode
diff --git a/packages/astro/src/core/endpoint/index.ts b/packages/astro/src/core/endpoint/index.ts
index 4f3c5b075..71a21850b 100644
--- a/packages/astro/src/core/endpoint/index.ts
+++ b/packages/astro/src/core/endpoint/index.ts
@@ -161,7 +161,7 @@ function isRedirect(statusCode: number) {
 }
 
 export function throwIfRedirectNotAllowed(response: Response, config: AstroConfig) {
-	if (!isServerLikeOutput(config) && isRedirect(response.status)) {
+	if (!isServerLikeOutput(config) && isRedirect(response.status) && !config.experimental.redirects) {
 		throw new AstroError(AstroErrorData.StaticRedirectNotAvailable);
 	}
 }
diff --git a/packages/astro/src/prerender/routing.ts b/packages/astro/src/prerender/routing.ts
index 928789044..3c0e1f8a4 100644
--- a/packages/astro/src/prerender/routing.ts
+++ b/packages/astro/src/prerender/routing.ts
@@ -1,6 +1,7 @@
 import type { AstroSettings, RouteData } from '../@types/astro';
-import { preload, type DevelopmentEnvironment } from '../core/render/dev/index.js';
+import { preload, type DevelopmentEnvironment, type ComponentPreload } from '../core/render/dev/index.js';
 import { getPrerenderStatus } from './metadata.js';
+import { routeIsRedirect, RedirectComponentInstance } from '../core/redirects/index.js';
 
 type GetSortedPreloadedMatchesParams = {
 	env: DevelopmentEnvironment;
@@ -26,14 +27,31 @@ type PreloadAndSetPrerenderStatusParams = {
 	matches: RouteData[];
 	settings: AstroSettings;
 };
+
+type PreloadAndSetPrerenderStatusResult = {
+	filePath: URL;
+	route: RouteData;
+	preloadedComponent: ComponentPreload;
+};
+
 async function preloadAndSetPrerenderStatus({
 	env,
 	matches,
 	settings,
-}: PreloadAndSetPrerenderStatusParams) {
+}: PreloadAndSetPrerenderStatusParams): Promise<PreloadAndSetPrerenderStatusResult[]> {
 	const preloaded = await Promise.all(
 		matches.map(async (route) => {
 			const filePath = new URL(`./${route.component}`, settings.config.root);
+
+			if(routeIsRedirect(route)) {
+				const preloadedComponent: ComponentPreload = [[], RedirectComponentInstance];
+				return {
+					preloadedComponent,
+					route,
+					filePath
+				};
+			}
+
 			const preloadedComponent = await preload({ env, filePath });
 
 			// gets the prerender metadata set by the `astro:scanner` vite plugin
@@ -46,7 +64,7 @@ async function preloadAndSetPrerenderStatus({
 				route.prerender = prerenderStatus;
 			}
 
-			return { preloadedComponent, route, filePath } as const;
+			return { preloadedComponent, route, filePath };
 		})
 	);
 	return preloaded;
diff --git a/packages/astro/test/redirects.test.js b/packages/astro/test/redirects.test.js
index 5cff8fe3d..2e1e0b8b9 100644
--- a/packages/astro/test/redirects.test.js
+++ b/packages/astro/test/redirects.test.js
@@ -65,61 +65,93 @@ describe('Astro.redirect', () => {
 	});
 
 	describe('output: "static"', () => {
-		before(async () => {
-			process.env.STATIC_MODE = true;
-			fixture = await loadFixture({
-				root: './fixtures/ssr-redirect/',
-				output: 'static',
-				experimental: {
-					redirects: true,
-				},
-				redirects: {
-					'/one': '/',
-					'/two': '/',
-					'/blog/[...slug]': '/articles/[...slug]',
-					'/three': {
-						status: 302,
-						destination: '/',
+		describe('build', () => {
+			before(async () => {
+				process.env.STATIC_MODE = true;
+				fixture = await loadFixture({
+					root: './fixtures/ssr-redirect/',
+					output: 'static',
+					experimental: {
+						redirects: true,
 					},
-				},
+					redirects: {
+						'/one': '/',
+						'/two': '/',
+						'/blog/[...slug]': '/articles/[...slug]',
+						'/three': {
+							status: 302,
+							destination: '/',
+						},
+					},
+				});
+				await fixture.build();
+			});
+	
+			it('Includes the meta refresh tag in Astro.redirect pages', async () => {
+				const html = await fixture.readFile('/secret/index.html');
+				expect(html).to.include('http-equiv="refresh');
+				expect(html).to.include('url=/login');
+			});
+	
+			it('Includes the meta refresh tag in `redirect` config pages', async () => {
+				let html = await fixture.readFile('/one/index.html');
+				expect(html).to.include('http-equiv="refresh');
+				expect(html).to.include('url=/');
+	
+				html = await fixture.readFile('/two/index.html');
+				expect(html).to.include('http-equiv="refresh');
+				expect(html).to.include('url=/');
+	
+				html = await fixture.readFile('/three/index.html');
+				expect(html).to.include('http-equiv="refresh');
+				expect(html).to.include('url=/');
+			});
+	
+			it('Generates page for dynamic routes', async () => {
+				let html = await fixture.readFile('/blog/one/index.html');
+				expect(html).to.include('http-equiv="refresh');
+				expect(html).to.include('url=/articles/one');
+	
+				html = await fixture.readFile('/blog/two/index.html');
+				expect(html).to.include('http-equiv="refresh');
+				expect(html).to.include('url=/articles/two');
+			});
+	
+			it('Generates redirect pages for redirects created by middleware', async () => {
+				let html = await fixture.readFile('/middleware-redirect/index.html');
+				expect(html).to.include('http-equiv="refresh');
+				expect(html).to.include('url=/');
 			});
-			await fixture.build();
-		});
-
-		it('Includes the meta refresh tag in Astro.redirect pages', async () => {
-			const html = await fixture.readFile('/secret/index.html');
-			expect(html).to.include('http-equiv="refresh');
-			expect(html).to.include('url=/login');
-		});
-
-		it('Includes the meta refresh tag in `redirect` config pages', async () => {
-			let html = await fixture.readFile('/one/index.html');
-			expect(html).to.include('http-equiv="refresh');
-			expect(html).to.include('url=/');
-
-			html = await fixture.readFile('/two/index.html');
-			expect(html).to.include('http-equiv="refresh');
-			expect(html).to.include('url=/');
-
-			html = await fixture.readFile('/three/index.html');
-			expect(html).to.include('http-equiv="refresh');
-			expect(html).to.include('url=/');
 		});
 
-		it('Generates page for dynamic routes', async () => {
-			let html = await fixture.readFile('/blog/one/index.html');
-			expect(html).to.include('http-equiv="refresh');
-			expect(html).to.include('url=/articles/one');
-
-			html = await fixture.readFile('/blog/two/index.html');
-			expect(html).to.include('http-equiv="refresh');
-			expect(html).to.include('url=/articles/two');
-		});
+		describe('dev', () => {
+			/** @type {import('./test-utils.js').DevServer} */
+			let devServer;
+			before(async () => {
+				process.env.STATIC_MODE = true;
+				fixture = await loadFixture({
+					root: './fixtures/ssr-redirect/',
+					output: 'static',
+					experimental: {
+						redirects: true,
+					},
+					redirects: {
+						'/one': '/',
+					},
+				});
+				devServer = await fixture.startDevServer();
+			});
 
-		it('Generates redirect pages for redirects created by middleware', async () => {
-			let html = await fixture.readFile('/middleware-redirect/index.html');
-			expect(html).to.include('http-equiv="refresh');
-			expect(html).to.include('url=/');
+			after(async () => {
+				await devServer.stop();
+			});
+	
+			it('Returns 301', async () => {
+				let res = await fixture.fetch('/one', {
+					redirect: 'manual'
+				});
+				expect(res.status).to.equal(301);
+			});
 		});
 	});